Contactor failure detecting apparatus for fuel cell system

• US 8,435,687 B2
• Filed: 11/24/2010
• Issued: 05/07/2013
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ojima, Kuniaki, Sasaki, Minoru
• Primary Examiner(s): Conley, Helen O
• Application Number:
  US12/954,043
• Publication Number:
  US 20110070513A1
• Time in Patent Office: 895 Days
• Field of Search: 429/432, 429/431, 429/430
• US Class Current: 429/432
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04686 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A contactor electrically connects and disconnects a fuel cell from a load. When a failure-detecting mode for detecting a closing failure of a contactor is initiated, an opening command is transmitted to the contactor, and a DC/DC converter connected to a motor changes the load voltage. Then, the load voltage and a fuel cell voltage are compared with each other. If the contactor is in a normal open state, as a result of the opening command, the fuel cell voltage is constant, whereas the load voltage of the DC/DC converter decreases, thereby producing a voltage difference. A closing failure of the contactor is determined when it is detected that the fuel cell voltage is substantially equal to the load voltage.

Claims

1. A contactor failure detecting apparatus for use in a fuel cell system comprising:

a fuel cell operated to generate power by reaction of a fuel gas and an oxygen-containing gas;

a load driven by an output from said fuel cell;

a contactor that is opened and closed in order to electrically connect and disconnect said fuel cell with respect to said load, said contactor having one end connected to an output side of said fuel cell and another end connected to said load;

a DC/DC converter capable of voltage variable control or current variable control, having one end thereof connected to a load side of said contactor and another end thereof connected to an energy storage device; and

a control device,

wherein said control device is configured to transmit an opening command to said contactor while said contactor is in a closed state, thereafter lowers the voltage on a load side of said DC/DC converter, and detects a closing failure of said contactor, when the voltage of the fuel cell changes, when the current flows out from the fuel cell, or when the voltage on the load side of the DC/DC converter does not become smaller than the voltage of the fuel cell.

2. A contactor failure detecting apparatus for use in a fuel cell system according to claim 1, wherein, when said control device changes either a voltage or a current on said load side of said DC/DC converter, said control device controls a change in said voltage or in said current on said load side of said DC/DC converter such that an electrical power of said fuel cell is smaller than a predetermined electrical power limit value.

3. A contactor failure detecting apparatus for use in a fuel cell system according to claim 1, further comprising:

an air compressor for supplying said oxygen-containing gas to said fuel cell, connected to said load side through an electrical input side of said air compressor,

wherein, while detecting a closing failure of said contactor, said control device drives said air compressor for scavenging said fuel cell.